Method and Device for Retransmission

1. A method comprising: repeating a transmission of a previously transmitted data transfer unit by a device after a predetermined number of other data transfer units has been transmitted by the device; determining whether a measure for a time period since the first transmission of the data transfer unit by the device has exceeded a predetermined threshold; and providing a final transmission of the previously transmitted data transfer unit based on a determining that the measure for the time period has exceeded the predetermined threshold.

2. The method according to claim 1 , wherein the repeating of the transmission of the previously transmitted data transfer unit is provided until the providing of the final transmission, when no acknowledgement has been received by the device from a retransmission return channel for the previously transmitted data transfer unit.

3. The method according to claim 1 , wherein the repeating of the transmission is implemented in a physical layer of a Digital Subscriber Line (DSL) communication system.

4. The method according to claim 1 , wherein the previously transmitted data transfer unit is no longer eligible for retransmission when a final transmission of the previously transmitted data transfer unit has been provided based on the determining that the time period has exceeded the predetermined threshold.

5. The method according to claim 1 , wherein a repeating of a transmission after a transmission of a predetermined number of other data transfer units is provided for all data transfer units transmitted by the device for which no acknowledgement has been received from a retransmission return channel.

6. A device comprising: a retransmission entity, the retransmission entity to determine for a data transfer unit in a retransmission queue of a device whether a measure for a time period since the first transmission of the data transfer unit by the device exceeds a predetermined limit and being further to provide a final transmission of the data transfer unit if it is determined for the data transfer unit that the measure for a time period since the first transmission exceeds a predetermined limit.

7. The device according to claim 6 , wherein the retransmission entity is to provide the final transmission of the data transfer unit in a next available transmission of a data transfer unit by the device.

8. The device according to claim 6 , wherein the device is to cyclically retransmit the data transfer unit prior to a final transmission.

9. The device according to claim 8 , wherein the device is to transmit a predetermined fixed number of other data transfer units between two retransmissions of the data transfer unit, when the data transfer unit is cyclically retransmitted.

10. The device according to claim 6 , wherein the device is configured such that the final transmission is provided n transmissions before the last possible transmission of the data transfer unit, where n is an integer and the last possible transmission being determined by a second configurable limit to be the last transmission in which the data transfer unit is eligible for retransmission.

11. The device according to claim 6 , wherein the device is to provide a marking information associated with the data transfer unit based on selecting of the data transfer unit for a final transmission, wherein the retransmission entity is to provide no further retransmission of the data transfer unit based on the marking information.

12. A device comprising: a transmitter capable of transferring a plurality of information related to a retransmission return message from the device to a further device; wherein the device is to provide in a first mode for at least one first information of the plurality of information a predefined value; and to provide in a further mode for the at least one first information a value which is derived from at least one data transfer unit received by the device from the further device.

13. The device according to claim 12 , wherein the first information is derived in the further mode from a sequence of received data transfer units by using a predetermined scheme, wherein the predefined value is a value which would be obtained by the predetermined scheme when a predetermined number of data transfer units is previously received correct.

14. The device according to claim 12 , wherein the at least one first information includes at least one information of the group of information which comprises: an acknowledge bit for acknowledging a correct receiving of the last received data transfer unit, an acknowledge bit for acknowledging a correct receiving of the second to last received data transfer unit, an absolute count number of the last received data transfer unit, and a number indicating a number of consecutive correctly received data transfer units in the past.

15. The device according to claim 12 , further to determine based on the receiving of one or more data transfer units whether the first mode or the further mode is to be applied; and the device further to provide the at least one first information in accordance with the determining whether the first mode or the further mode is to be applied.

16. The device according to claim 12 , wherein when more than one but less than a specified number of data transfer units has been received by the first device from the second device, the plurality of information includes at least one information which is calculated based on the received data transfer units and a predetermined number of virtual received data transfer units, the virtual received data transfer units being assumed to be virtual received correct prior to the receiving of the first receiving of a data transfer unit.